36v to 48v with a 12v battery?

[jfw432]

Correct. Brakes spin free and bearings were replaced since one had a light hiccup but it certainly wasn't dragging. Differential seems to spin smooth as well but not sure how much resistance that is really supposed to have.

And thanks...I may try to just pull one of my car batteries out and see what it does.

[jfw432]

So I finally got around to dropping my old truck battery in the cart today. The cart hauls butt up the hill now. Is there any potential of damaging any of the batteries in this configuration? Probably gets a total of 4-5 minutes of run time a week.

[radioman]

Weak batteries will not deliver the voltage going up the hill. I don't believe adding another 12 volt battery and the charging arrangement is a good idea. More attention needs to be directed to the 6 volt batteries. Check each individual battery's voltage one at a time under load going up the hill as suggested in post #3. Heavy duty this and that is not going to produce the performance they are capable of if the batteries are not doing the job.

[jfw432]

Originally Posted by radioman

Weak batteries will not deliver the voltage going up the hill. I don't believe adding another 12 volt battery and the charging arrangement is a good idea. More attention needs to be directed to the 6 volt batteries. Check each individual battery's voltage one at a time under load going up the hill as suggested in post #3. Heavy duty this and that is not going to produce the performance they are capable of if the batteries are not doing the job.

Thought I answered that question already. They are all within about .1 volt of each other both at rest and under load. All are on the same page and have been since day 1 when I bought them and was having these same issues. I guess there is a chance that all of the brand new batteries were garbage but I find that hard to believe.

The plan will be to charge the 6v batteries like normal with the 36v charger and the 12v battery separately. Obviously, this will make charging more work but spending a couple minutes disconnecting and reconnecting batteries every couple weeks over having a useless cart is still preferable in my book...unless someone can shed some light on what's actually going on.

When these batteries die, I'll look into getting a true 48v setup.

[mgray70]

Originally Posted by jfw432

The batteries have fallen off a bit over the past few years since I bought them but they are still within .1 of each other. The pack is around 37.5 and they do drop to around 31v on the hill. Even when they were brand new, I recorded the amp output on the hill and it was peaking at around 265 which I thought was pretty poor.

The batteries are Powertron p2000 which obviously aren't as good as Trojans but surely they aren't complete garbage...right?

I think this post answers your question. I'm not really an expert, but 37.5 volts is considered pretty low considering a fully charged pack should be 38.2, and should only drop 3-4 volts under load. You say it's dropping to around 31 which is getting mighty close to the low voltage cut off. Maybe it's time to go ahead with the 48 volt upgrade with 6-8 volts.

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[kernal]

Hey guys, the way the OP uses the cart seems to be pretty unique. It just goes up and down a relatively short steep hill once in awhile. OP states 4-5 minutes of use a week. Range is of no importance at all. He's just boosting the voltage with an additional battery for the trip up and charging it separately from the pack. In fact I believe you could make a case that he doesn't need specific golf cart batteries at all although they are probably cheaper than alternatives.

What y'all are saying is true for the average user but I think this case is pretty much one of kind.

[radioman]

Originally Posted by jfw432

Thought I answered that question already. They are all within about .1 volt of each other both at rest and under load. All are on the same page and have been since day 1 when I bought them and was having these same issues. I guess there is a chance that all of the brand new batteries were garbage but I find that hard to believe.

The plan will be to charge the 6v batteries like normal with the 36v charger and the 12v battery separately. Obviously, this will make charging more work but spending a couple minutes disconnecting and reconnecting batteries every couple weeks over having a useless cart is still preferable in my book...unless someone can shed some light on what's actually going on.

When these batteries die, I'll look into getting a true 48v setup.

You wont have long to wait if you charge them every couple of weeks. That may be your problem. Your batteries are probably half shot. It is best to charge them after each use. If the extra battery helps you prolong the use of the cart that's good.

[mgray70]

Originally Posted by kernal

Hey guys, the way the OP uses the cart seems to be pretty unique. It just goes up and down a relatively short steep hill once in awhile. OP states 4-5 minutes of use a week. Range is of no importance at all. He's just boosting the voltage with an additional battery for the trip up and charging it separately from the pack. In fact I believe you could make a case that he doesn't need specific golf cart batteries at all although they are probably cheaper than alternatives.

What y'all are saying is true for the average user but I think this case is pretty much one of kind.

I agree that the extra battery will be a temporary fix, I'm just pointing to the problem. I wouldn't want to do it, but if it buys him some time, go for it.

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[Sergio]

jfw432, You don't need to disconnect any cables to charge, just leave the original receptacle wired to the 6x6v batteries and connect the 12v charger directly to the 12v battery.

It makes no difference that the 12v battery has a cable going to the 6v battery, all batteries will charge according to their respective chargers.

As mentioned, charging the batteries at the end of each day You use the cart will help.

[radioman]

Originally Posted by Sergio

jfw432, You don't need to disconnect any cables to charge, just leave the original receptacle wired to the 6x6v batteries and connect the 12v charger directly to the 12v battery.

It makes no difference that the 12v battery has a cable going to the 6v battery, all batteries will charge according to their respective chargers.

As mentioned, charging the batteries at the end of each day You use the cart will help.

That is a good idea.